From Utrecht Central:

Take the sprinter towards The Hague Central Station and get off at Vleuten station.

Bus 111 – from Vleuten Station:
Take Bus 111 toward Kasteel de Haar; from there, it’s a 1-minute walk to the Kasteel de Haar reception desk. Bus 111 runs daily, year-round, every hour during the day until approximately 7:00 p.m. During the Christmas break and the period between Easter and the end of summer vacation, Bus 111 even runs twice an hour during the day.

Please note: To make sure your bus is running, it’s best to plan your trip via 9292ov.nl.

From Amsterdam Central:

Take the train from Amsterdam to Breukelen station.

Bus 111 - from Breukelen station
Take bus 111 to Castle de Haar, from there it's a 1-minute walk to the reception of Castle de Haar. Bus 111 runs daily, all year round, during the day every hour until approximately 7 pm. During the Christmas vacations and in the period between Easter and the end of the summer vacations, bus 111 runs twice an hour during the day.

Please note: To make sure your bus is running, it’s best to plan your trip via 9292ov.nl.

OV bike:

Prefer biking? At stations Vleuten, Woerden and Breukelen you can easily rent an OV bike for a bike ride to the castle. See own transport for more information.